The present invention relates to an aluminum alloy not only having a higher electrical resistance but also excellent formability, for example, press formability, bending formability, in comparison with heretofore available aluminum alloys.
Aluminum alloys have been heretofore used as a good conductor because of their low electrical resistance as compared to iron and iron alloys. However, in recent years, aluminum alloys have been extensively used in other applications.
In the case of use under high magnetic field, aluminum alloys having an increased electrical resistance are requested. The use of aluminum alloys under such condition causes induced current corresponding to variation of the magnetic field and the aluminum alloys will be affected by the external force resulting from the actions of the magnetic field and the electrical field. Since the external force is proportional to the induced current density, it is necessary to minimize the current density. For this reason, it has been very important to increase the electrical resistance.
Conventional Al-Mg type practical aluminum alloys have a specific resistance under 6.4 .mu..OMEGA..cm (IACS of over 27%).
Previous investigations which are described in a pending application proved that an addition of lithium is very effective in increasing electrical resistance. But, addition of lithium in a large amount results in a decrease in ductility and, accordingly, will reduce elongation below 10%. Therefore, there is a keen demand for the development of high electrical resistance aluminum alloys having highly improved ductility and formability.